# Multiple Abstraction Level Retrieve Augment Generation

arXiv: https://arxiv.org/abs/2501.16952 · HTML: https://mlsanity.com/paper/2501.16952/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- Placed in RAG robustness and adaptive retrieval, one of 15 directions in Retrieval-augmented generation.
- First posted on arXiv 28 Jan 2025.

## Placed in

- Retrieval-augmented generation / [RAG robustness and adaptive retrieval](https://mlsanity.com/rag/rag-robustness-and-adaptive-retrieval/)

## Built on by (most cited first, 4 of 4)

- [From Web Search towards Agentic Deep Research: Incentivizing Search with Reasoning Agents](https://mlsanity.com/paper/2506.18959/) (2025)
- [Beyond Protein Language Models: An Agentic LLM Framework for Mechanistic Enzyme Design](https://mlsanity.com/paper/2511.19423/) (2025)
- [SmartChunk Retrieval: Query-Aware Chunk Compression with Planning for Efficient Document RAG](https://mlsanity.com/paper/2602.22225/) (2025)
- [Uncertainty-Aware Hybrid Retrieval for Long-Document RAG](https://mlsanity.com/paper/2606.13550/) (2026)

## Abstract (arXiv)

A Retrieval-Augmented Generation (RAG) model powered by a large language model (LLM) provides a faster and more cost-effective solution for adapting to new data and knowledge. It also delivers more specialized responses compared to pre-trained LLMs. However, most existing approaches rely on retrieving prefix-sized chunks as references to support question-answering (Q/A). This approach is often deployed to address information needs at a single level of abstraction, as it struggles to generate answers across multiple levels of abstraction. In an RAG setting, while LLMs can summarize and answer questions effectively when provided with sufficient details, retrieving excessive information often leads to the 'lost in the middle' problem and exceeds token limitations. We propose a novel RAG approach that uses chunks of multiple abstraction levels (MAL), including multi-sentence-level, paragraph-level, section-level, and document-level. The effectiveness of our approach is demonstrated in an under-explored scientific domain of Glycoscience. Compared to traditional single-level RAG approaches, our approach improves AI evaluated answer correctness of Q/A by 25.739% on Glyco-related papers.